Treatment of 2,6-Dimethylaniline by Electrochemical-Assisted Fenton-Like Process

Abstract

This paper reports on the comparison of Fenton-like and electrochemical-assisted Fenton processes on 2,6-dimethylaniline removal. The influences of initial pH, ferric ion, hydrogen peroxide, and electric current on the oxidation of 2,6-dimethylaniline were also evaluated to determine the optimum operating parameters. Results showed that oxidation efficiency of the electro-Fenton process was better than the Fenton process. The experimental data revealed that increasing ferric ions, hydrogen peroxide concentration, and applied electric current enhanced the oxidation efficiency. However, too much ferric ion and hydrogen peroxide decreased the removal efficiency because of the scavenging effects that occur in the solution. When the electric current was increased to 5 A, the regeneration of ferrous ions decreased. This was because a too-high electric current resulted in water electrolysis and reduced the current efficiency of ferric reduction and therefore increased power cost. The results also showed that low pH is preferred for 2,6-dimethylaniline degradation, and increasing the initial pH from 1.5 to 2.0 increased the regeneration of ferrous ion. However, when the initial pH was increased to 3.0, the ferrous ion easily reacted with hydroxide and then generated iron oxide, leading to a decrease in the ferrous concentration. In addition, the experiments also revealed that the greatest 2,6-dimethylaniline removal was achieved when 1 mM of ferric ion, 20 mM of hydrogen peroxide, and a current of 1 A at pH 2 were applied. Consequently, the electro-Fenton process is a viable alternative in the degradation of 2,6-dimethylaniline.